He wrote: "I spoke with President Moon of South Korea last night. Asked him how Rocket Man is doing.

"Long gas lines forming in North Korea. Too bad!"

He appears to have been making a reference to Elton John classic Rocket Man.

His comments also suggested increased sanctions recently passed by the UN restricting North Korea's gas and oil imports were having an effect.

Meanwhile, White House advisers said the isolated nation would face destruction unless it shelves its weapons programmes and threats of war.

Trump's chief diplomat held out hope the North would return to the bargaining table, though the president's envoy to the United Nations said the Security Council had "pretty much exhausted" all its options.

Kim Jong Un has pledged to continue the North's programmes, saying his country is nearing its goal of "equilibrium" in military force with the United States.

Asked about Trump's description of Kim, national security adviser H.R. McMaster said "Rocket Man" was "a new one and I think maybe for the president."

But, he said, "that's where the rockets are coming from. Rockets, though, we ought to probably not laugh too much about because they do represent a great threat to all."

McMcaster said Kim is "going to have to give up his nuclear weapons because the president has said he's not going to tolerate this regime threatening the United States and our citizens with a nuclear weapon."

Asked if that meant Trump would launch a military strike, McMaster said "he's been very clear about that, that all options are on the table."

Kim has threatened Guam, a US territory in the Pacific, and has fired missiles over Japan, a US. ally.

North Korea also recently tested its most powerful bomb.

The UN Security Council has voted unanimously twice in recent weeks to tighten economic sanctions on North Korea, including targeting shipments of oil and other fuel used in missile testing.

Trump has threatened to rain "fire and fury" on North Korea if the North continued with its threats.

We pay for your stories! Do you have a story for The Sun Online news team? Email us at tips@the-sun.co.uk or call 0207 782 4368